diff --git a/components/bt/host/bluedroid/common/include/common/bt_target.h b/components/bt/host/bluedroid/common/include/common/bt_target.h
index 83abc9ba8c..22de4d6c7b 100644
--- a/components/bt/host/bluedroid/common/include/common/bt_target.h
+++ b/components/bt/host/bluedroid/common/include/common/bt_target.h
@@ -1578,7 +1578,7 @@
 
 /* ERTM Tx window size */
 #ifndef RFC_FCR_OPT_TX_WINDOW_SIZE
-#define RFC_FCR_OPT_TX_WINDOW_SIZE  20
+#define RFC_FCR_OPT_TX_WINDOW_SIZE  10
 #endif
 
 /* ERTM Maximum transmissions before disconnecting */
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_fcr.c b/components/bt/host/bluedroid/stack/l2cap/l2c_fcr.c
index ecf0bd6c68..aafb4b380d 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_fcr.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_fcr.c
@@ -928,6 +928,9 @@ static BOOLEAN process_reqseq (tL2C_CCB *p_ccb, UINT16 ctrl_word)
                 full_sdus_xmitted++;
             }
             osi_free(p_tmp);
+            if (p_ccb->cong_sent) {
+                l2cu_check_channel_congestion(p_ccb);
+            }
         }
 
         /* If we are still in a wait_ack state, do not mess with the timer */
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c b/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
index ea887b036e..06eebe80b2 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
@@ -3613,6 +3613,9 @@ void l2cu_set_acl_hci_header (BT_HDR *p_buf, tL2C_CCB *p_ccb)
 void l2cu_check_channel_congestion (tL2C_CCB *p_ccb)
 {
     size_t q_count = fixed_queue_length(p_ccb->xmit_hold_q);
+#if (CLASSIC_BT_INCLUDED == TRUE)
+    size_t q_waiting_ack_count = fixed_queue_length(p_ccb->fcrb.waiting_for_ack_q);
+#endif
 
 #if (L2CAP_UCD_INCLUDED == TRUE)
     if ( p_ccb->local_cid == L2CAP_CONNECTIONLESS_CID ) {
@@ -3625,7 +3628,11 @@ void l2cu_check_channel_congestion (tL2C_CCB *p_ccb)
         /* If this channel was congested */
         if ( p_ccb->cong_sent ) {
             /* If the channel is not congested now, tell the app */
-            if (q_count <= (p_ccb->buff_quota / 2)) {
+            if (q_count <= (p_ccb->buff_quota / 2)
+#if (CLASSIC_BT_INCLUDED == TRUE)
+                        && (p_ccb->peer_cfg.fcr.mode == L2CAP_FCR_BASIC_MODE || q_waiting_ack_count < p_ccb->our_cfg.fcr.tx_win_sz)
+#endif
+                    ) {
                 p_ccb->cong_sent = FALSE;
                 if (p_ccb->p_rcb && p_ccb->p_rcb->api.pL2CA_CongestionStatus_Cb) {
                     L2CAP_TRACE_DEBUG ("L2CAP - Calling CongestionStatus_Cb (FALSE), CID: 0x%04x  xmit_hold_q.count: %u  buff_quota: %u",
@@ -3664,7 +3671,11 @@ void l2cu_check_channel_congestion (tL2C_CCB *p_ccb)
         } else {
             tL2C_LCB *p_lcb = p_ccb->p_lcb;
             /* If this channel was not congested but it is congested now, tell the app */
-            if (q_count > p_ccb->buff_quota || (p_lcb && (p_lcb->link_xmit_data_q) && (list_length(p_lcb->link_xmit_data_q) + q_count) > p_ccb->buff_quota)) {
+            if (q_count > p_ccb->buff_quota || (p_lcb && (p_lcb->link_xmit_data_q) && (list_length(p_lcb->link_xmit_data_q) + q_count) > p_ccb->buff_quota)
+#if (CLASSIC_BT_INCLUDED == TRUE)
+                    || (p_ccb->peer_cfg.fcr.mode != L2CAP_FCR_BASIC_MODE && q_waiting_ack_count >= p_ccb->our_cfg.fcr.tx_win_sz)
+#endif
+                    ) {
                 p_ccb->cong_sent = TRUE;
                 if (p_ccb->p_rcb && p_ccb->p_rcb->api.pL2CA_CongestionStatus_Cb) {
                     L2CAP_TRACE_DEBUG ("L2CAP - Calling CongestionStatus_Cb (TRUE),CID:0x%04x,XmitQ:%u,Quota:%u",